The final track of the album, it was released as the B-side to the song "Over My Head". It was a hard rock song, quite atypical of Fleetwood Mac's songs (at least following the Peter Green era), but it quickly became a live staple, appearing as the concert finale to nearly all of their tours, often in a greatly extended form. The song was intended for a second Buckingham Nicks album, but was used for Fleetwood Mac instead. It appeared on all live albums recorded after its release, including Live, The Dance, Fleetwood Mac: Live in Boston, and on the 2015 box set of Tusk. The live edition from The Dance was released in an edited form on the US and 2009 release of the greatest hits compilation album The Very Best of Fleetwood Mac.

Buckingham also includes the song in his solo live performances, as well releasing versions on solo live albums Live at the Bass Performance Hall, Songs from the Small Machine: Live in L.A. and One Man Show. The song deals with themes of fear and paranoia. The main melody bears a strong resemblance to the melody of the song "This Little Babe" written by Benjamin Britten, which is part of the suite A Ceremony of Carols, composed in 1942.

The studio version of the song is in G natural minor, but live versions are usually in F natural minor. On recent tours the song has been played in D minor.

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Wikipedia